PNNL News Center - Recent News Releases from Pacific Northwest National Laboratoryhttp://www.pnnl.gov/news/
A feed of Pacific Northwest National Laboratory press releases and top stories from around the lab.en-usWed, 25 Feb 2015 21:21:19 GMTWed, 25 Feb 2015 21:21:19 GMTPacific Northwest National Laboratoryhttp://www.pnnl.gov/images/pnnl_logo_battelle.pnghttp://www.pnnl.gov
242123http://www.pnnl.gov/news/release.aspx?id=4182
Ensuring the power grid keeps the lights on in large cities could be easier with a new battery design that packs far more energy than any other battery of its kind and size.

The new zinc-polyiodide redox flow battery, described in Nature Communications, uses an electrolyte that has more than two times the energy density of the next-best flow battery used to store renewable energy and support the power grid. And its energy density is approaching that of a type of lithium-ion battery used to power portable electronic devices and some small electric vehicles.

"With improved energy density and inherent fire safety, flow batteries could provide long-duration energy storage for the tight confines of urban settings, where space is at a premium," said Imre Gyuk, energy storage program manager at the Department of Energy's Office of Electricity Delivery and Energy Reliability, which funded this research. "This would enhance the resiliency and flexibility of the local electrical grid."

"Another, unexpected bonus of this electrolyte's high energy density is it could potentially expand the use of flow batteries into mobile applications such as powering trains and cars," said the study's corresponding author, Wei Wang, a materials scientist at DOE's Pacific Northwest National Laboratory.

Going with the flow

Both flow and lithium-ion batteries were invented in the 1970s, but only the lithium-ion variety took off at that time. Lithium-ion batteries could carry much more energy in a smaller space than flow batteries, making them more versatile. As a result, lithium-ion batteries have been used to power portable electronics for many years. And utilities have begun using them to store the increasing amounts of renewable energy generated at wind farms and solar power facilities.

But the high-energy lithium-ion batteries' packaging can make them prone to overheating and catching fire. Flow batteries, on the other hand, store their active chemicals separately until power is needed, greatly reducing safety concerns. This feature has prompted researchers and developers to take a serious second look at flow batteries.

Like other flow batteries, the zinc-polyiodide battery produces power by pumping liquid from external tanks into the battery's stack, a central area where the liquids are mixed. The external tanks in PNNL's new battery hold aqueous electrolytes, watery solutions with dissolved chemicals that store energy.

When the battery is fully discharged, both tanks hold the same electrolyte solution: a mixture of the positively charged zinc ions, Zn2+, and negatively charged iodide ion, I-. But when the battery is charged, one of the tanks also holds another negative ion, polyiodide, I3-. When power is needed, the two liquids are pumped into the central stack. Inside the stack, zinc ions pass through a selective membrane and change into metallic zinc on the stack's negative side. This process converts energy that's chemically stored in the electrolyte into electricity that can power buildings and support the power grid's operations.

To test the feasibility of their new battery concept, Wei and his PNNL colleagues created a small battery on a lab countertop. They mixed the electrolyte solution, separating a black zinc-polyiodide liquid and a clear zinc-iodide liquid in two glass vials as miniature tanks. Hoses were connected between the vials, a pump and a small stack.

They put the 12-watt-hour capacity battery — comparable to about two iPhone batteries — through a series of tests, including determining how different concentrations of zinc and iodide in the electrolyte affected energy storage. Electrical capacity is measured in watt-hours; electric cars use about 350 watt-hours to drive one mile in the city.

More power to it

The demonstration battery put out far more energy for its size than today's most commonly used flow batteries: the zinc-bromide battery and the vanadium battery. PNNL's zinc-polyiodide battery also had an energy output that was about 70 percent that of a common lithium-ion battery called a lithium iron phosphate battery, which is used in portable electronics and in some small electric vehicles.

Lab tests revealed the demonstration battery discharged 167 watt-hours per liter of electrolyte. In comparison, zinc-bromide flow batteries generate about 70 watt-hours per liter, vanadium flow batteries can create between 15 and 25 watt-hours per liter, and standard lithium iron phosphate batteries could put out about 233 watt-hours per liter. Theoretically, the team calculated their new battery could discharge even more — up to 322 watt-hours per liter — if more chemicals were dissolved in the electrolyte.

Safe and versatile, but not perfect yet

PNNL's zinc-polyiodide battery is also safer because its electrolyte isn't acidic like most other flow batteries. It's nearly impossible for the water-based electrolyte to catch fire and it doesn't require expensive materials that are needed to withstand the corrosive nature of other flow batteries.

Another advantage of PNNL's new flow battery is that it can operate in extreme climates. The electrolyte allows it to work well in temperatures as cold as -4 degrees Fahrenheit and as warm as +122 degrees. Many batteries have much smaller operating windows and can require heating and cooling systems, which cut into a battery's net power production.

One problem the team encountered was a build-up of metallic zinc that grew from the central stack's negative electrode and went through the membrane, making the battery less efficient. Researchers reduced the buildup, called zinc dendrite, by adding alcohol to the electrolyte solution.

Managing zinc dendrite formation will be a key in enabling PNNL's zinc-polyiodide battery to be used in the real world. Wei and his colleagues will continue to experiment with different alcohols and other additives and use advanced instruments to characterize how the battery's materials respond to those additives. The team will also build a larger, 100-watt-hour model of the battery for additional testing.

]]>Wed, 25 Feb 2015 14:15:00 GMT4182http://www.pnnl.gov/news/release.aspx?id=4181
Dendrites — the microscopic, pin-like fibers that cause rechargeable batteries to short circuit — create fire hazards and can limit the ability of batteries to power our smart phones and store renewable energy for a rainy day.

Now a new electrolyte for lithium batteries that's described in Nature Communications eliminates dendrites while also enabling batteries to be highly efficient and carry a large amount of electric current. Batteries using other dendrite-limiting solutions haven't been able to maintain both high efficiencies and current densities.

"Our new electrolyte helps lithium batteries be more than 99 percent efficient and enables them to carry more than ten times more electric current per area than previous technologies," said physicist Ji-Guang "Jason" Zhang of the Department of Energy's Pacific Northwest National Laboratory. "This new discovery could kick-start the development of powerful and practical next-generation rechargeable batteries such as lithium-sulfur, lithium-air and lithium-metal batteries."

Battery 101

Most of the rechargeable batteries used today are lithium-ion batteries, which have two electrodes: one that's positively charged and contains lithium and another, negative one that's typically made of graphite. Electricity is generated when electrons flow through a wire that connects the two. To control the electrons, positively charged lithium atoms shuffle from one electrode to the other through another path: the electrolyte solution in which the electrodes sit. But graphite has a low energy storage capacity, limiting the amount of energy a lithium-ion battery can provide smart phones and electric vehicles.

When lithium-based rechargeable batteries were first developed in the 1970s, researchers used lithium for the negative electrode, which is also known as an anode. Lithium was chosen because it has ten times more energy storage capacity than graphite. Problem was, the lithium-carrying electrolyte reacted with the lithium anode. This caused microscopic lithium dendrites to grow and led the early batteries to fail.

Many have tweaked rechargeable batteries over the years in an attempt to resolve the dendrite problem. In the early 1990s, researchers switched to other materials such as graphite for the anode. More recently, scientists have also coated the anode with a protective layer, while others have created electrolyte additives. Some solutions eliminated dendrites, but also resulted in impractical batteries with little power. Other methods only slowed, but didn't stop, the fiber's growth.

Concentrated secret sauce

Thinking today's rechargeable lithium-ion batteries with graphite anodes could be near their peak energy capacity, PNNL is taking another look at the older designs. Zhang and his team sought to develop an electrolyte that worked well in batteries with a high-capacity lithium anode. They noted others had some success with electrolytes with high salt concentrations and decided to use large amounts of the lithium bis(fluorosulfonyl)imide salt they were considering. To make the electrolyte, they added the salt to a solvent called dimethoxyethane.

The researchers built a circular test cell that was slightly smaller than a quarter. The cell used the new electrolyte and a lithium anode. Instead of growing dendrites, the anode developed a thin, relatively smooth layer of lithium nodules that didn't short-circuit the battery.

After 1,000 repeated charge and discharge cycles, the test cell retained a remarkable 98.4 percent of its initial energy while carrying 4 milliAmps of electrical current per square centimeter of area. They found greater current densities resulted in slightly lower efficiencies. For example, a current density as high as 10 milliAmps per square centimeter, the test cell maintained an efficiency of more than 97 percent. And a test cell carrying just 0.2 milliAmps per square centimeter achieved a whopping 99.1 percent efficiency. Most batteries with lithium anodes operate at a current density of 1 milliAmps per square centimeter or less and fail after less than 300 cycles.

Anode-free battery?

The new electrolyte's remarkably high efficiency could also open the door for an anode-free battery, Zhang noted. The negative electrodes in today's batteries actually consist of thin pieces of metal such as copper that are coated in active materials such as graphite or lithium. The thin metal bases are called current collectors, as they are what keep electrons flowing to power our cell phones. Active materials have been needed to coat the electrodes because, so far, most electrolytes have been inefficient and continue to consume lithium ions during battery operation. But an electrolyte with more than 99 percent efficiency means there's potential to create a battery that only has a negative current collector, without an active material coating, on the anode side.

"Not needing an anode could lower the cost and size of rechargeable batteries and would also significantly improve the safety of these batteries," Zhang said.

The electrolyte needs to be refined before it's ready for mainstream use, however. Zhang and his colleagues are evaluating various additives to further enhance their electrolyte so a lithium battery using it could achieve more than 99.9 percent efficiency, a level that's needed for commercial adoption. They are also examining which cathode materials would work best in combination with their new electrolyte.

]]>Tue, 24 Feb 2015 17:02:00 GMT4181http://www.pnnl.gov/news/release.aspx?id=4180
Developing renewable fuel from wet algae and enabling analysis of complex liquids are two of the latest innovations Pacific Northwest National Laboratory has successfully driven to the market with the help of commercial partners.

As a result, the Federal Laboratory Consortium has honored the Department of Energy national laboratory with two 2015 Excellence in Technology Transfer awards. The consortium is a nationwide network that encourages federal laboratories to transfer laboratory-developed technologies to commercial markets.

The consortium selected PNNL's two technologies from 57 nominations nationwide to be among 16 winners. PNNL has earned a total of 81 such awards since the program began in 1984. The 2015 awards will be presented April 29 at the consortium's annual meeting in Denver, Colorado.

Scientists and engineers at PNNL have created a process that produces biocrude oil minutes after they pour in a slurry of green algae.

The continuous process uses heat and pressure to chemically and physically change the algae to biocrude, mimicking the way Earth made crude oil millions of years ago. The biocrude can then be turned into aviation fuel, gasoline and diesel using conventional refining technology.

PNNL teamed with Utah-based Genifuel Corporation to ready this technology for industry-their collaborative research led to two joint patents. With the new designs, Genifuel built a pilot plant for Reliance Industries Ltd. in Colorado, where the company plans to test the technology before producing renewable biofuel on a larger scale.

The process can be applied to other forms of wet materials as well, such as sludge from wastewater, dairy farms or food processing, increasing the potential impact of this technology. More companies have approached Genifuel about using PNNL's process.

The team recognized for transferring this process includes: PNNL's Doug Elliott, Dan Anderson, Todd Hart, Andy Schmidt and Eric C. Lund; and James Oyler, president of Genifuel Corporation. The Department of Energy's Bioenergy Technology Office provided funding to develop the algae-to-biocrude process.

In the vacuum of instruments like scanning electron microscopes, liquid samples boil away, evaporating before they can be studied. Now PNNL's System for Analysis at the Liquid Vacuum Interface, or SALVI, allows these instruments to-for the first time-image liquid samples in real time and a realistic environment.

The idea for SALVI came when PNNL scientists wanted to study atmospheric particles called aerosols, but they quickly realized their device could help other researchers gain new insights about nanoparticles, bacteria, cells, batteries and more.

To make their technology available for the broader scientific community, PNNL worked with Pennsylvania-based Structure Probe Inc. The analytical equipment supplier licensed the associated patents and adapted PNNL's design to offer a commercial product called Wet Cell II. The first orders of their product will ship this year.

SALVI is small enough to fit in your hand. The device can take as little as two drops of a sample and flow that liquid through a channel to a window the size of a pinhole. There, the ion beam of an instrument can analyze the sample. The small window and flow reduce evaporation in a vacuum.

PNNL won an R&D 100 Award for SALVI, naming it one of the 100 most innovative scientific and technological breakthroughs in 2014.

The team recognized for transferring SALVI to the market includes: PNNL's Xiao-Ying Yu, Bruce Harrer and Zihua Zhu; and Li Yang, former PNNL scientist. Gene Rodek of Structure Probe Inc. also played an important role in bringing the technology to the commercial market. SALVI was developed in collaboration with scientists at EMSL, DOE's Environmental Molecular Sciences Laboratory user facility at PNNL.

]]>Fri, 30 Jan 2015 15:52:00 GMT4180http://www.pnnl.gov/news/release.aspx?id=4179
Fish no longer need to go under the knife to help researchers understand exactly how they swim through hydroelectric dams, thanks to a new injectable tracking device described today in the journal Scientific Reports.

The new injectable acoustic fish tag allows researchers to safely and quickly insert the small device into young fish with a syringe similar to those used to treat humans. Injecting the tag, instead of surgically inserting it as earlier versions required, is less invasive and enables fish to heal faster, which can also provide more reliable information about fish behavior.

"Our new tag essentially allows fish to undergo a quick outpatient procedure," said Zhiqun "Daniel" Deng, a scientist at the Department of Energy's Pacific Northwest National Laboratory. "Tags have been used to track and evaluate fish movement for decades, but this is the first acoustic transmitter that can be inserted with a simple needle injection."

Salmon sound system

PNNL began developing its Juvenile Salmon Acoustic Telemetry System, also known as JSATS, in 2001 at the request of the U.S. Army Corps of Engineers' Portland District, which operates several dams in the Pacific Northwest. That system — which includes tags, sound receivers and software — was initially designed to provide a more accurate picture of how young salmon migrate from their birthplace in Columbia River Basin waters to the open Pacific Ocean. The system's use has since expanded to other fish species, for a variety of waterpower structures, and beyond the Northwest, including in California, Australia and Brazil.

Tags release quiet beeps that are picked up by receivers placed in rivers, lakes and other water bodies as tagged fish swim by. Receiver data helps researchers map out the precise 3-D location of each fish and determine if fish are injured during their travels. That information can help make dams more fish-friendly by revising their operations or altering their physical structure. Hundreds of thousands of young fish have been studied with JSATS tags over the years.

Though the earlier JSATS tag provided a very detailed picture of fish migration, researchers worried that the mere presence of their tag — which was about three times heavier in 2007 than today's injectable tag — could alter fish behavior and make tag-gathered data less reliable for small fish. The earlier tags were also large enough to require surgery, with technicians creating a small incision into each anesthetized fish, manually inserting tags and hand-stitching incisions closed. Studies showed surgically tagged fish might not behave the same as untagged fish if the ratio of the tag weight to fish weight is too big. As a result, PNNL staff worked to make a progressively smaller and lighter tag, with the eventual goal of being able to inject their tag with a syringe.

"Minimizing the impact dams have on fish requires us to study and understand how changes at dams affect their behavior and survival. A critical assumption of any research is that the animals being studied represent their entire population," said M. Brad Eppard, a fisheries biologist with the Portland District of the U.S. Army Corps of Engineers and a co-author on the paper. "The new injectable tag helps us ensure the individual fish we study represent the fish in the Federal Columbia River Power System by allowing smaller-sized fish to be tagged."

Tricked-out tags

PNNL's new injectable tag is about as big as two grains of rice placed next to each other lengthwise. It weighs just 217 milligrams when dry, is 15 millimeters long and 3.38 millimeters in diameter. Half of the cylindrical tag contains a tiny 3-volt battery. The other half consists of a miniature circuit board and a transducer, which makes the tag's beeping noise. New features include the addition of a temperature sensor and the ability to adjust sound levels, release two unique tracking codes alternatively, and program the tag to be silent for a pre-determined amount of time.

The injectable tag can intermittently beep as often as every 0.4 seconds, or less frequently, depending on a study's particular needs. Thanks to the new tag's powerful battery, lab tests showed the tag can release sound for an average of 120 days when beeps are sent every three seconds. In comparison, PNNL's previous tag only lasted 23 days under the same conditions.

Inserting the new tag into fish also takes substantially less time than the previous version. Injecting the tag with a syringe takes just 20 seconds, while the old tag's surgery required at least two minutes. The shorter period reduces the cost of fish-tagging studies, as the manual labor of handling fish and inserting tags is the most expensive part of these studies.

Fishing for the right size

During the summer of 2013, about 700 juvenile salmon implanted with the injectable tag were released in the Snake River in Washington state. Initial results indicated survival was higher in fish carrying the injectable tag than those with the older tag. Research is ongoing to fully evaluate how the tags affect fish and to determine the smallest fish that is suitable for safe injectable tagging.

PNNL intends to transfer the new injectable tag to a commercial vendor that will independently manufacture and sell it. Discussions are ongoing with several companies that have expressed interest in licensing the technology.

Deng and his team are continually working to improve their fish tag. An even smaller tag is being developed for juvenile eels and lamprey, and a longer-lasting tag was made for juvenile sturgeon last year.

]]>Thu, 29 Jan 2015 15:09:00 GMT4179http://www.pnnl.gov/news/release.aspx?id=4178
Coating the mouth with BPA-containing food, like soup, does not lead to higher than expected levels of BPA in blood, a new study in Toxicology and Applied Pharmacology shows. The study authors conclude that oral exposure does not create a risk for high exposures.

BPA, also known as bisphenol A, is used to make some plastics and to seal canned food containers against bacterial contamination. Food, which picks up trace amounts of BPA from packaging, is the major source of human exposure.

Health concerns about BPA center on its potential to mimic certain hormones at really high exposures. But within the last month, the European Food Safety Authority and the U.S. Food and Drug Administration reaffirmed their earlier decisions that BPA is safe as used in food packaging materials.

A 2013 study in dogs, however, focused attention on the possibility that their conclusions might be based on incorrect assumptions about how much BPA gets into the human body from food and beverages.

"Regulatory agency conclusions about the safety of BPA were questioned, with increasing frequency and intensity, after publication of the dog study," said toxicologist Justin Teeguarden of the Department of Energy's Pacific Northwest National Laboratory, author of the current study in humans.

The authors of the dog study placed concentrated solutions of BPA under the tongues of sleeping beagles for an extended period. The amount of absorption and the amount of the active form of BPA measured in blood was higher than in previous studies in rodents, monkeys and humans. The authors hypothesized that this meant the amount of BPA in human blood could be higher than regulatory agencies assumed, an idea that became the basis for questioning the regulatory decisions.

"Testing this hypothesis, in humans, became necessary," said Teeguarden.

Because the dog study challenged conclusions regarding BPA exposure in humans, Teeguarden and his colleagues set out to determine if absorption of BPA from tissues of the mouth increased BPA blood levels in humans. His colleagues included a team led by Daniel Doerge at the FDA's National Center for Toxicological Research in Jefferson, Arkansas.

"Our goal was to mimic normal eating behavior, assuring that the results of the study would apply to humans eating and drinking," said Teeguarden. "This was something that was not possible in the dog study."

To fully coat the oral cavity, 10 male volunteers ate warmed tomato soup in which researchers had placed a traceable form of BPA. They took multiple blood and urine samples over a 24 hour period.

The team found that coating the mouth in this way did not lead to higher levels of the active form of BPA in blood. As in all human studies to date, the body inactivated 998 out of every 1000 BPA molecules by the time BPA entered the bloodstream.

"Just as important, we confirmed that there is no merit to hypotheses that BPA accumulates in humans. The entire dose of BPA was eliminated in urine within 24 hours, with no evidence of accumulation," said Teeguarden.

The study is the second from this multi-institutional team that looked at BPA absorption and metabolism in humans ingesting BPA. The earlier study was funded by the Environmental Protection Agency under the Science to Achieve Results program. The current study was funded by the American Chemistry Council.

"The study design is novel, the measurements are comprehensive, and the results are conclusive regarding the issue of oral absorption. Our confidence in the conclusions comes, in no small part, from the fact that our results are remarkably similar to those from the earliest studies in humans conducted by Doctors Wolfgang Völkel and Dekant in 2002 and 2005, our previous study, and new preliminary data from the National Toxicology Program," said Teeguarden.

"This latest study contributes new measurements in humans that confirm and extend the body of animal and human data and analyses establishing that BPA levels in human blood are even lower than those considered safe by regulatory agencies," Teeguarden added. "Still, as we have said before, there could be some exposure settings, for example hospitals where plastics are routinely used in medical procedures, where exposures could be higher than in the general populations."

Overall, the work affirms the positions of regulatory agencies. "Our study reinforces the accuracy of conclusions made by the European Food Safety Authority, the FDA, the World Health Organization, and others, about the extent and nature of BPA exposure, absorption and metabolism. It follows that if objective, evidence-based decisions are valued, regulatory agency determinations that BPA is safe as used for food contact applications are not challengeable on the basis of uncertainties in oral exposure."

]]>Tue, 27 Jan 2015 18:01:00 GMT4178http://www.pnnl.gov/news/release.aspx?id=4177
Nature packs away carbon in chalk, shells and rocks made by marine organisms that crystallize calcium carbonate. Now, research suggests that the soft, organic scaffolds in which such crystals form guide crystallization by soaking up the calcium like an "ion sponge," according to new work in Nature Materials. Understanding the process better may help researchers develop advanced materials for energy and environmental uses, such as for removing carbon dioxide from the atmosphere.

Using a powerful microscope that lets researchers see the formation of crystals in real time, a team led by the Department of Energy's Pacific Northwest National Laboratory found that negatively charged molecules — such as carbohydrates found in the shells of mollusks — control where, when, and how calcium carbonate forms.

These large macromolecules do so by directing where calcium ions bind in the scaffold. The negative charge on the macromolecules attract the positively charged calcium ions, placing them in the scaffold through so-called ion binding. Rather than these chemical interactions, researchers had previously thought the scaffold guides crystallization by providing the best energetic environment for the crystal.

"This whole story is different from what we had believed to be the case," said lead researcher Jim De Yoreo at PNNL. "Ion binding defines a completely different mechanism for controlling crystallization than does making a perfect interface between the crystal and the scaffold. And it is one that should provide us with considerable control."

Missing Piece

Previous work showed that calcium carbonate takes multiple routes to becoming a mineral. All of the common crystal forms, including calcite (found in limestone), aragonite (found in mother-of-pearl), and vaterite (found in gallstones), crystallized from solution, often at the same time. But in some cases, droplet-like particles of uncrystallized material known as amorphous calcium carbonate, or ACC, formed first and then transformed into either aragonite or vaterite.

Those experiments, however, lacked a crucial element found in the biological world, where minerals form within an organic scaffold. For example, pearls develop in the presence of negatively charged carbohydrates and proteins from the oyster.

In addition, biologically built minerals often start out as ACC. De Yoreo and his colleagues wondered what role macromolecules — carbs, proteins or other large molecules with a negative charge — play.

To find out, De Yoreo and team allowed calcium carbonate to mineralize under a specialized transmission electron microscope at the Molecular Foundry, a DOE Office of Science User Facility at DOE's Lawrence Berkeley National Laboratory. Collaborators also hailed from Eindhoven University of Technology in The Netherlands.

But this time they added a negatively charged macromolecule, a polymer called polystyrene sulfonate. Without the polymer, they saw crystals of vaterite and a little calcite forming randomly under the microscope. With the polymer, however, ACC always appeared first and vaterite formed much later.

Because the polymer interfered with vaterite formation, the team looked a little closer at what the polymer was doing. When they mixed the polymer with the calcium first before introducing carbonate, they found globules of the polymer forming in the solution. They determined that the polymer had soaked up more than half of the calcium to form the globules.

When the researchers then added carbonate to the experimental chamber, ACC formed instead and it only appeared within these globules. The ACC grew in size until the supply of calcium ran out. The researchers concluded that calcium binding to the polymer is the key to forming the ACC and controlling where it forms.

Mineral Motivation

The team realized that controlling crystallization by attracting calcium ions to the macromolecules was not the way researchers had long thought it happened.

There are two main ways that calcium carbonate molecules might be persuaded to come together to form a mineral. One is by providing an environment where the atoms assemble in the crystal in the least energetic way possible, sort of like organizing a classroom full of schoolchildren by having them sit in seats arranged neatly in rows side-by-side in the corner of the room.

Another is via chemical binding — negatively or positively charged atoms or molecules called ions attract one another, sort of like waving popsicles in front of those kids to gather them in one spot.

Researchers had long suspected that organic scaffolds caused calcium carbonate to mineralize and find its most stable form, calcite, by creating low energy surfaces where the ions could easily arrange themselves in rows side-by-side. In fact, scientists had seen this previously with highly organized films of organic molecules.

But in this study, the polymer, like the popsicle, pulls in the calcium before minerals can form and turns it into ACC. This showed the researchers that ion binding can completely overwhelm any lower-energy advantage that crystallization on or outside of the polymer might confer.

"This is definitely another means of controlling nucleation," said De Yoreo. "Carbonate ions follow the calcium into the globules. They don't crystallize outside the globules because there's not enough calcium there to make a mineral. It's like bank robbers out for a heist. They go where the money is."

"This work opens new avenues for the investigation of biomineralization. Can we extend these experiments beyond the simple polymers we used here? To what extent can we rebuild parts of the biological machinery inside the microscope?" said co-author Prof. Nico Sommerdijk of Eindhoven University of Technology. "Answering these questions may eventually allow us to understand the biological mineral formation and apply its principles to design green, sustainable routes for the production of advanced materials."

This work was supported by the U.S. Department of Energy Office of Science and the Dutch Science Foundation.

]]>Mon, 26 Jan 2015 16:51:00 GMT4177http://www.pnnl.gov/news/release.aspx?id=4176
In the midst of the California rainy season, scientists are embarking on a field campaign designed to improve the understanding of the natural and human-caused phenomena that determine when and how the state gets its precipitation. They will do so by studying atmospheric rivers, meteorological events that include the famous rainmaker known as the Pineapple Express.

CalWater 2015 is an interagency, interdisciplinary field campaign starting January 14, 2015. CalWater 2015 will entail four research aircraft flying through major storms while a ship outfitted with additional instruments cruises below. The research team includes scientists from Scripps Institution of Oceanography at UC San Diego, the Department of Energy's Pacific Northwest National Laboratory, NOAA, and NASA and uses resources from the DOE's Atmospheric Radiation Measurement (ARM) Climate Research Facility, a national scientific user facility.

The two-month-long study will help provide a better understanding of how California gets its rain and snow, how human activities are influencing precipitation, and how the new science provides potential to inform water management decisions relating to drought and flood.

"We are collecting this data to improve computer models of rain that represent many complex processes and their interactions with the environment," said PNNL's Ruby Leung, who leads the DOE-funded portion. "Atmospheric rivers contribute most of the heavy rains along the coast and mountains in the West. We want to capture those events better in our climate models used to project changes in extreme events in the future."

]]>Fri, 16 Jan 2015 23:47:00 GMT4176http://www.pnnl.gov/news/release.aspx?id=4175
Three scientists at the Department of Energy's Pacific Northwest National Laboratory have been elected to the rank of Fellow in the American Physical Society. David Asner, Don Baer and Chris Mundy were selected for the honor, which recognizes exceptional contributions to physics, including outstanding research, important applications of physics, leadership or service to the physics community or significant contributions to physics education.

Asner's research focuses on searching for new particles, new interactions and new phenomena by understanding the most fundamental parts of the universe. He leads high energy particle physics experiments that re-create the conditions found in the first fraction of a second after the Big Bang. Technology transfer from particle physics plays a role in a wide variety of areas, including the Web, grid computing (the predecessor to cloud computing), and new medical therapies, devices, and diagnostics that improve and extend human life.

Baer's research advanced the molecular-level understanding of environmentally important interactions between nanoparticles and contaminants, mineral dissolution and material cracking. His research has applications to removing contaminants in water and understanding the impacts of nanoparticles on biological systems.

Mundy's research focuses on the complex processes that occur at the air-water interface. He was recognized for using quantum mechanics tools to form a molecular picture of the structure and dynamics of this important interface. Understanding these interfaces plays an important role in weather, medicine, and innovative materials that are exploited in the emerging field of nanoscience.

PNNL now has 13 active staff members who hold the rank of APS Fellow. The three new members will be honored at their division meetings in 2015.

APS works to advance knowledge of physics through its research journals, scientific meetings, and education, outreach, advocacy and international activities. The organization has more than 50,000 members and selection as an APS Fellow is limited to no more than one half of one percent of the membership each year.

]]>Thu, 15 Jan 2015 16:14:00 GMT4175http://www.pnnl.gov/news/release.aspx?id=4174
First responders have downloaded more than 10,000 copies of a guide to commercially available, hand-portable biodetection technologies created to help them determine what they might be up against in the field. Since many first responders do not always have immediate access to a computer, a mobile version of the guide is now available for cell phones and tablets.

"The new app will provide easier access to the updated report which is a valuable product-buying guide for first responders and purchasing specialists," said Cindy Bruckner-Lea, PNNL principal investigator. "With dozens of companies, technologies and sampling products listed, the guide provides a convenient and useful resource to fire fighters, law enforcement and hazardous materials response teams."

First responders know that white powder scenarios — or suspected biological threats — require quick and decisive action. Having the right field equipment available to identify suspicious substances can be complicated, challenging and expensive. The report summarizes and compares an extensive list of commercially available, hand-portable technologies.

The release of the mobile app is one part of a larger effort at PNNL to assess hand-portable, commercial, off-the-shelf biodetection technology. PNNL is evaluating a wide range of technologies from general protein tests for biological material to agent-specific tests such as immunoassay and polymerase chain reaction assays.

PNNL's "ground-up approach" involves first responders and stakeholders early in the process and culminates in the transition of information and knowledge in an effort to improve in-field detection of biological agents and toxins in suspicious powders.

]]>Thu, 08 Jan 2015 16:50:00 GMT4174http://www.pnnl.gov/news/release.aspx?id=4173
How much energy was used to heat the water for your morning shower is probably the least of your groggy, uncaffeinated thoughts.

However, some homeowners are discovering they have even less need to think about early-morning energy use thanks to an increasingly popular alternative to conventional electric water heaters — the heat pump water heater. Results from a new field study are challenging an earlier understanding that heat pump water heaters are efficient no matter how they're installed. It turns out using ducting for air intake and exhaust impacts both the appliance's and an entire home's energy use.

"Heat pump water heaters can use up to 63 percent less energy than traditional electric water heaters," said the study's lead researcher, Sarah Widder, of the Department of Energy's Pacific Northwest National Laboratory. "When water heating makes up about 18 percent of U.S. residential energy use, heat pump water heaters offer a real opportunity for energy savings."

Until now, many have thought those savings would be offset by an increased use in heating systems. That's because heat pump water heaters work by transferring heat from the air into water, which can lower indoor temperatures. This can reduce energy use during the hot summer months, but lead us to heat our homes more in the winter. But PNNL's field tests showed that, depending on how heat pump water heaters are connected to exterior ducting, they can reduce a home's overall power use. The results also showed heat pump water heaters may not affect a home's heating and cooling systems as much as previously thought.

New water heater in town

Due to their high efficiency, heat pump water heaters can be much less expensive to operate than electric resistance water heaters, the large, tall cylinders that warm water in 41 percent of U.S. homes. Heat pump water heaters are increasingly being installed in lieu of their conventional electric cousins. Heat pump water heaters make up about 1 percent of new water heater sales nationwide. The total number of units sold increased from 34,000 in 2012 to 43,000 in 2013, according to ENERGY STAR.

Before PNNL's field study, the only data on the impact heat pump water heaters have on whole-home energy use was from an idealized computer model that didn't draw on real-world data. To take a deeper look at total energy consumption, Widder and her colleagues installed heat pump water heaters in the PNNL Lab Homes, two especially equipped manufactured homes used to evaluate energy-efficient technologies.

A heat pump water heater was installed in one of the homes without any ducting whatsoever. Another, identical water heater was installed in the second home with one of two configurations: ducting that only vented the appliance's exhaust, or full ducting that both collected outside air and later exhausted used air back outside. Both homes used the same electric resistance heating, cooling and ventilation system.

Sensors placed in each of the Lab Homes measured energy use, indoor and outdoor temperatures, humidity and more. Computers controlling both homes periodically ran hot water and turned on lights to simulate actual occupancy identically in both homes. The PNNL team ran the experiment through the summer and winter of 2013.

Some ducts help, some hurt

Compared with the unducted water heater, the team found fully ducting a heat pump water heater reduced a home's total annual energy use by 4.2 percent. This provided a 10-year cost savings of $1,982 for the 1,500-square-foot home. Additionally, the researchers were surprised to find exhaust-only ducting actually increased a home's overall energy use by 2.9 percent. This represents an estimated $1,305 increase in total home energy costs over 10 years.

The team determined the exhaust-only ducting essentially created a vacuum within the home. Exhaust that was expelled outside through a duct had to be replaced with other air that was drawn in from the outdoors through cracks and holes in the homes' exterior walls. Because the outdoor air was colder than the air the heat pump spit out, exhaust ducting meant the homes' heating and cooling systems had to work harder to maintain comfortable indoor temperatures.

Results also revealed the heat pump water heaters' cooling effect was limited. Both of the homes' average interior temperatures were nearly identical during the experiment, varying by less than 1 degree Fahrenheit in both winter and summer. The researchers concluded this may have partially been because the water heaters were placed in a closet. Being closed off in a separate room could have created a buffer, which would have largely limited cooling to the air immediately around the appliance. More significant cooling occurred within the water heater closet. The unducted water heater's closet experienced temperatures about 5 degrees Fahrenheit cooler in the summer and about 8 degrees cooler in the winter.

"Unless you place a heat pump water heater in the middle of your living room and you sit right next to it, you probably won't feel a chill," Widder said.

Though their field study revealed some surprising data, Widder and her colleagues noted more information is needed to better evaluate the energy efficiency of heat pump water heaters. The study was limited to the climate of Richland, Washington, where the PNNL Lab Homes are located, and to the layout and design of the Lab Homes. Field tests in a variety of homes and climates would provide better data, they said. Additional field data, combined with a more detailed computer model, could offer the information needed to draw broader conclusions for best practices to install heat pump water heaters in the Northwest and the whole nation, the authors noted.

This research was funded by the Department of Energy's Office of Energy Efficiency and Renewable Energy and the Bonneville Power Administration.

]]>Tue, 06 Jan 2015 23:09:00 GMT4173http://www.pnnl.gov/news/release.aspx?id=4172
The Department of Energy's Pacific Northwest National Laboratory directly and indirectly supported more than $1.3 billion and 6,800 jobs in the Washington state economy last year, as well as another $1.2 billion dollars and over 6,400 jobs through closely related economic activities.

Those and other findings regarding PNNL's economic impact on the Evergreen State are the subject of a comprehensive analysis prepared by laboratory economists and released this week. The report, titled "Economic Impact of Pacific Northwest National Laboratory on the State of Washington in Fiscal Year 2013" can be viewed here.

"The community has long recognized the economic impact of PNNL is significant. Seeing the impact actually quantified in this report should be a real eye-opener here locally and to the entire region," said Carl Adrian, president and CEO of the Tri-City Development Council. "PNNL is really an economic engine for all of Washington and I hope business leaders and legislators from across the entire state recognize PNNL's impact in terms of spending, employment, in-state purchases and taxes paid."

PNNL is one of Washington's largest scientific research centers. Interdisciplinary teams at PNNL address many of America's most pressing issues in energy, the environment and national security through advances in basic and applied science. Seventy percent of its funding comes from DOE, while the rest is sponsored by the Department of Homeland Security, National Institutes of Health, Nuclear Regulatory Commission, and other federal agencies and private industry. PNNL is currently celebrating its 50th anniversary, and is managed and operated by Battelle for DOE's Office of Science. The laboratory is the largest employer in the Tri-Cities and one of the largest in eastern Washington.

Of PNNL's 4,344 staff, 94 percent reside in Washington, working mostly at PNNL's main campus in Richland, but also at its Marine Sciences Laboratory in Sequim and offices on Lake Union in Seattle. The laboratory's unique facilities attract thousands of visiting scientists each year, who, according to the report, also help fuel the local and state economy.

Report Highlights

Highlights from the report include the following. Data in most cases are for fiscal year 2013 (Oct. 1, 2012 through Sept. 30, 2013) and in some cases calendar year 2013, which was the latest available data at the time the report was compiled.

Expenditures in Washington state were about $377 million in salaries and wages, and $48 million in purchased goods and services. Through multiplier effects, these direct expenditures supported $1.31 billion in total economic output in Washington state.

An additional $1.21 billion in economic output was created by PNNL-related health care, spinoff companies, visitors and retirees in Washington.

Seventy-six spinoff companies located in Washington earned an estimated $570 million in revenue and employed 2,219 people,

PNNL, as well as Battelle staff at PNNL, paid nearly $23 million in taxes to state and local governments,

Nearly 200,000 visitor-days at PNNL from university, industry and government partners and others led to $31 million in visitor spending, and about 450 jobs supported by visitor spending,

Battelle, as the operator of PNNL, received $5.6 million in royalty income and license fees, which were reinvested in the laboratory and communities where it has a presence,

PNNL staff and their households spent $42 million in purchase of health-related services funded by PNNL health insurance in fiscal year 2013,

Retired staff living in Washington state spent over $22 million through Medicare and other health providers in 2013,

Battelle and Battelle staff at PNNL contributed more than $1 million to philanthropic and civic organizations. This included $324,000 for science, technology, engineering, and mathematics, or STEM, education.

Clark is currently a Regents Professor in the Chemistry Department at Washington State University in Pullman, and a scientist at WSU's Nuclear Radiation Center. She begins a joint appointment with PNNL on January 1, 2015. Once fully transitioned to PNNL in June, she will maintain a joint appointment with WSU allowing her to continue preparing the next generation of nuclear scientists.

"Clark's background complements PNNL's internationally recognized core capabilities in nuclear science, which underpin the lab's research in energy, the environment and national security," said Jud Virden, associate laboratory director for Energy and Environment. "Her unique expertise in nuclear materials and analytics strategically aligns with several challenging programs facing the Department of Energy."

Clark was appointed by President Obama to the U.S. Nuclear Waste Technical Review Board, serving from 2011 through October 2014. She is a Fellow of the American Chemical Society and of the American Association for the Advancement of Science. She was elected to the Washington State Academy of Sciences in 2010 and currently serves on its board of directors.

Clark will join PNNL as a Battelle Fellow — the Lab's highest recognition for scientific and technological achievement — a rank shared by only nine other PNNL scientists who have distinguished themselves as internationally recognized leaders in their fields.

Clark will lead PNNL's new Nuclear Process Science Initiative, which will focus on creating a fundamental scientific understanding of the key processes that underlie waste processing and the nuclear forensics challenges that are central to DOE's environmental management and non-proliferation missions.

The initiative will leverage distinctive capabilities associated with its Radiochemical Processing Laboratory — one of only two DOE Office of Science Hazard Category 2 Non-Reactor Nuclear Facilities capable of multi-disciplinary research and development. Clark will also focus on combining RPL capabilities with other PNNL radiological facilities and with the radiochemistry annex in EMSL, the Environmental Molecular Sciences Laboratory — a national scientific user facility sponsored by the Department of Energy's Office of Science.

]]>Mon, 15 Dec 2014 15:56:00 GMT4171http://www.pnnl.gov/news/release.aspx?id=4170
Scientists from the Department of Energy's Pacific Northwest National Laboratory will present a variety of research at the 2014 American Geophysical Union Fall Meeting, which runs Monday, Dec. 15 through Friday, Dec. 19 at the Moscone Convention Center in San Francisco. Noteworthy PNNL research presentations include the following topics:

Even with global warming cold air outbreaks will remain

Just because the climate is warming doesn't mean Cold Air Outbreaks are going away, especially in Southwestern Canada and Northwestern United States. Overall, global climate models agree that there will be a dip in the duration of Cold Air Outbreaks across North America, but the percentage of decrease is consistently smaller from Western Canada to the Upper Midwest of the United States — a region with a higher number of CAOs historically. PNNL researcher Yang Gao and colleagues found that increased frequency of atmospheric blocking over Alaska, Yukon and the Gulf of Alaska may contribute to CAO events in the future in those areas. Using a high resolution regional climate model, the PNNL study shows that despite a general decrease in mean snowfall in a warmer future climate, snow cover in the mountainous west that precedes the onset of CAO will still play a role in the development of CAO events in future.

As governments and industry look to deep underground storage of carbon dioxide as a possible way to reduce greenhouse gases in the atmosphere, researchers at PNNL are studying if CO2 could cause harm underground. The team studied whether CO2 leaked from a sequestration site below an aquifer could increase contaminants such as arsenic and cadmium in drinking water. CO2 by itself isn't harmful — after all, we drink it in soda. Yet once dissolved, it increases the acidity of groundwater enough to change how it reacts with minerals and contaminants. Experimenting on sediment samples from aquifers above potential sequestration sites in Kansas and Texas, the researchers found the overall change in chemistry was not harmful. The results suggest that CO2 bubbled into the aquifer in Kansas would not release contaminants found naturally in the sediments. Even if CO2 leaked into the aquifer together with storage contaminants, the gas did not prevent these sediments from sucking out the contaminants like a sponge. Experiments on samples from the Texas aquifer found CO2 dissolves calcite present in the sediments — effectively stabilizing groundwater in a way that discourages contaminant release. The team suggests studying every potential sequestration site before use, because variability in sediment composition could make a difference. In addition to this experimental research, PNNL is modeling reactions as a part of a larger project to assess the environmental impacts of carbon sequestration.

Environmental and health science communities are separate by design-one focuses on a body of work the size of a planet; the other on a much smaller, though equally complex, fleshy subject. But scientists can learn more about how the environment impacts human health if these two fields collaborate more often, says Ghassem Asrar. As director of the Joint Global Change Research Institute, a collaboration of PNNL and the University of Maryland, Asrar is no stranger to organizing impactful research-in fact, he will receive an AGU Ambassador Award this year for such leadership. Yet he and colleagues at the National Institutes of Health face a unique challenge: bringing together two fields that have their own jargons and research methods. Once united, the teams could make discoveries like how pollutants in smog, Saharan dust, and natural pollen combine to affect respiratory health, or how multiple environmental factors impact the spread of infectious diseases, a major risk to human health. Asrar and his colleagues are promoting a holistic approach to research on the multifaceted topic of environment and human health.

Imagine the smell of pine wafting from a forest. That smell is part of a bouquet of biogenic volatile organic compounds emitted in huge amounts from a variety of plants — and field studies show they can have a significant impact on regional climates. In polluted air these BVOCs create a lot of aerosols — up to half or more of all particles in the air. These particles create something of an umbrella that reflects the sun's light back to space cooling the earth's surface. In certain areas, this effect could be completely masking the effects of warming due to increased CO2 levels. If the polluted air is cleaned, this mitigating effect would go away and the warming would be greater than currently observed. Data from PNNL studies and others will be used to improve representation of these processes in climate models.

Even in the remote Arctic Circle, sooty pollution from diesel-burning cars and trucks can have a significant impact on the climate. Soot, also known as black carbon, stands out among the bright, white snow and ice that covers most of the Arctic. Its tiny dark particles easily absorb sunlight, which heats the snow and ice it sits on and further exacerbates climate change. The Russian city of Murmansk is home to 300,000 people and is the largest Arctic city, making it an ideal spot to examine soot in the Arctic. PNNL researchers worked with colleagues from Russia's Murmansk State Technical University to conduct a detailed regional inventory of soot emissions from diesel sources. They found the local mining industry, which relies on many diesel-powered vehicles and machines to extract and transport ore, produces 70 percent of the area's black carbon emissions. The inventory will help inform the development of emission-reducing policies in Russia and other Arctic countries.

]]>Fri, 12 Dec 2014 15:44:00 GMT4170http://www.pnnl.gov/news/release.aspx?id=4169
A dozen stunning images depicting basic and applied research at the Department of Energy's Pacific Northwest National Laboratory are showcased in a 2015 computer wallpaper calendar and other digital products.

The images reflect advances in diverse research areas, ranging from clean energy to non-proliferation of nuclear materials, and from improving the electric grid to better understanding environmental processes.

The 12 images and the stories behind them can be downloaded and used as a 2015 wallpaper calendar on desktop and laptop computers, or as background images on tablets, phones and other devices. A downloadable PDF of the calendar is also available.

The photos were selected from more than 50 nominations during a contest held earlier this year at PNNL. All of the submissions can be viewed at PNNL's Flickr page.

This is the fourth successive year the national laboratory has produced a calendar.

]]>Mon, 08 Dec 2014 14:13:00 GMT4169http://www.pnnl.gov/news/release.aspx?id=3169
A new study will help researchers create longer-lasting, higher-capacity lithium rechargeable batteries, which are commonly used in consumer electronics. In a study published in the journal ACS Nano, researchers showed how a coating that makes high capacity silicon electrodes more durable could lead to a replacement for lower-capacity graphite electrodes.

"Understanding how the coating works gives us an indication of the direction we need to move in to overcome the problems with silicon electrodes," said materials scientist Chongmin Wang of the Department of Energy's Pacific Northwest National Laboratory.

Thanks to its high electrical capacity potential, silicon is one of the hottest things in lithium ion battery development these days. Replacing the graphite electrode in rechargeable lithium batteries with silicon could increase the capacity ten-fold, making them last many hours longer before they run out of juice. The problem? Silicon electrodes aren't very durable — after a few dozen recharges, they can no longer hold electricity.

That's partly due to how silicon takes up lithium — like a sponge. When charging, lithium infiltrates the silicon electrode. The lithium causes the silicon electrode to swell up to three times its original size. Possibly as a result of the swelling or for other unknown reasons, the silicon fractures and breaks down.

Researchers have been using electrodes made up of tiny silicon spheres about 150 nanometers wide — about a thousand times smaller than a human hair — to overcome some of the limitations of silicon as an electrode. The small size lets silicon charge quickly and thoroughly — an improvement over earlier silicon electrodes — but only partly alleviates the fracturing problem.

Last year, materials scientist Chunmei Ban and her colleagues at the National Renewable Energy Laboratory in Golden, Colorado, and the University of Colorado, Boulder found that they could cover silicon nanoparticles with a rubber-like coating made from aluminum glycerol. The coated silicon particles lasted at least five times longer — uncoated particles died by 30 cycles, but the coated ones still carried a charge after 150 cycles.

Researchers did not know how this coating improved the performance of the silicon nanoparticles. The nanoparticles naturally grow a hard shell of silicon oxide on their surface, much like stainless steel forms a protective layer of chromium oxide on its surface. No one understood if the oxide layer interfered with electrode performance, and if so, how the rubbery coating improved it.

To better understand how the coating worked, PNNL's Wang and colleagues, including Ban, turned to expertise and a unique instrument at EMSL, DOE's Environmental Molecular Sciences Laboratory, a DOE Office of Science User Facility at PNNL.

Ban's group — which developed the coating for silicon electrodes, called alucone, and is currently the only group that can create alucone-coated silicon particles — took high magnification images of the particles in an electron microscope. But Wang's team has a microscope that can view the particles in action, while they are being charged and discharged. So, Yang He from the University of Pittsburgh explored the coated silicon nanoparticles in action at EMSL.

The team discovered that, without the alucone coating, the oxide shell prevents silicon from expanding and limits how much lithium the particle can take in when a battery charges. At the same time, they found that the alucone coating softens the particles, making it easier for them to expand and shrink with lithium.

And the microscopic images revealed something else — the rubbery alucone replaces the hard oxide. That allows the silicon to expand and contract during charging and discharging, preventing fracturing.

"We were amazed that the oxide was removed," said Wang. "Normally it's hard to remove an oxide. You have to use acid to do that. But this molecular deposition method that coats the particles completely changed the protective layer."

In addition, the particles with the oxide shells tend to merge together during charging, increasing their size and preventing lithium from permeating the silicon. The rubbery coating kept the particles separated, allowing them to function optimally.

In the future, the researchers would like to develop an easier method of coating the silicon nanoparticles.

This work was supported by the DOE Office of Energy Efficiency and Renewable Energy and PNNL.

]]>Tue, 02 Dec 2014 14:50:00 GMT3169http://www.pnnl.gov/news/release.aspx?id=3168
In the Pacific Northwest, young salmon must dodge predatory birds, sea lions and more in their perilous trek toward the ocean. Hydroelectric dams don't make the trip any easier, with their manmade currents sweeping fish past swirling turbines and other obstacles. Despite these challenges, most juvenile salmon survive this journey every year.

Now, a synthetic fish is helping existing hydroelectric dams and new, smaller hydro facilities become more fish-friendly. The latest version of the Sensor Fish — a small tubular device filled with sensors that analyze the physical stresses fish experience — measures more forces, costs about 80 percent less and can be used in more hydro structures than its predecessor, according to a paper published today in the American Institute of Physics' Review of Scientific Instruments.

"The earlier Sensor Fish design helped us understand how intense pressure changes can harm fish as they pass through dam turbines," said lead Sensor Fish developer Daniel Deng, a chief scientist at the Department of Energy's Pacific Northwest National Laboratory.

"And the newly improved Sensor Fish will allow us to more accurately measure the forces that fish feel as they pass by turbines and other structures in both conventional dams and other hydro power facilities. As we're increasingly turning to renewable energy, these measurements can help further reduce the environmental impact of hydropower."

Abundant renewable resource

More than half of the United States' renewable energy came from hydropower in 2013, representing 7 percent of the nation's total power generation that year. The vast majority of that power came from traditional, large hydroelectric dams. Today, there is also a growing interest in small hydro facilities such as small dams that generate less than 10 megawatts of power and pumped storage hydroelectric plants.

Most large dams in the U.S. were built in the 1970s or earlier and will soon need to be relicensed — a process that includes evaluating and often reducing a dam's environmental impact. Key to that evaluation is examining how fish fare when swimming through dams.

PNNL began developing the Sensor Fish in the late 1990s to improve fish survival at hydroelectric dams along the Pacific Northwest's Columbia River Basin. The earliest design featured basic circuitry, sensors and two AA batteries encased in a six-inch-long, fish-shaped piece of clear rubber. Though the appearance was fish-like, the design didn't fully capture the experience of real juvenile salmon swimming through dams.

High-tech solution

So PNNL staff went back to the drawing board and devised the current, tubular design around 2004. Similar to the latest design, the 2004-issued Sensor Fish featured a hollow tube of clear, durable plastic that was stuffed with various sensors, a circuit board and a miniature rechargeable battery.

Using this version of the device, which has been dubbed the first-generation Sensor Fish, PNNL researchers measured the various forces juvenile salmon experience as they pass through dams. Back then, the Sensor Fish was specifically designed to evaluate dams equipped with a common type of turbine along the Columbia River, the Kaplan turbine. The pressure change, they found, is akin to traveling from sea level to the top of Mount Everest in blink of an eye.

Many people assume fish swimming through dams are only injured when turbine blades hit them, but PNNL's research has shown there are many different forces that can harm fish, including abrupt pressure changes in dam turbine chambers. That knowledge is helping redesign dam turbines so they create less severe pressure changes while maintaining or even improving power production. Many of America's aging hydroelectric dams will be undergoing retrofits in coming years that include installing newly designed turbines.

The need to retrofit old dams, combined with interest in building new hydropower facilities here and abroad, triggered a redesign of the Sensor Fish about three years ago. The latest version — called the second-generation Sensor Fish — can be used in different kinds of hydro facilities, including unconventional, smaller hydropower plants and conventional dams with either Kaplan or Francis dam turbines.

The new device also measures forces more precisely — it measures nearly twice as much pressure and acceleration as before, for example. And the Sensor Fish is now significantly cheaper to make: the revamped devices cost $1,200 each, while the earlier ones cost $5,000. Other features were also added, such as a temperature sensor, an orientation sensor, a radio transmitter and an automatic retrieval system that floats the device to the surface after a predetermined amount of time.

Test-proven, ready for the field

Researchers successfully field-tested the new and improved Sensor Fish in two Washington state dams: Ice Harbor on the Snake River and Boundary on the Pend Oreille River. Lab tests also showed the second-generation device worked well after facing up to 600 times the force of gravity.

Over the next year, the second-generation Sensor Fish is slated to evaluate three small hydro projects in the U.S., a conventional hydroelectric dam in the U.S., irrigation structures in Australia and a dam on the Mekong River in Southeast Asia.

Deng and his colleagues are currently manufacturing the new Sensor Fish by hand in PNNL's Bio-Acoustics & Flow Laboratory. To further reduce the Sensor Fish's cost and expand its use, PNNL would like to transfer the technology to a company that could manufacture it for hydropower operators and research institutions.

]]>Tue, 04 Nov 2014 20:34:00 GMT3168http://www.pnnl.gov/news/release.aspx?id=3167
People with muscular dystrophy could one day assess the effectiveness of their medication with the help of a smartphone-linked device, a new study in mice suggests. The study used a new method to process ultrasound imaging information that could lead to hand-held instruments that provide fast, convenient medical information.

In the study presented Oct. 30 at the Acoustical Society of America's annual meeting, researchers determined how well muscles damaged by muscular dystrophy responded to a drug in mice with an animal form of the disease. They did so by processing ultrasound data in a way appropriate for small, low-power and relatively inexpensive instruments. Called point-of-care devices, such instruments allow physicians to bring healthcare to the patient.

Physicist Michael S. Hughes of the Department of Energy's Pacific Northwest National Laboratory performed the work with colleagues John E. McCarthy, Jon N. Marsh, and Samuel A. Wickline while at Washington University in St. Louis, Missouri.

Although a small study involving animals, it builds on work in people that shows noninvasive ultrasound can track muscle health. Duchenne muscular dystrophy — often shortened to DMD — affects one out of 3500 male births. Steroids can help slow muscle degeneration, but too much medication causes other issues such as weight gain and high blood pressure.

"The result implies you can monitor drug therapy with cheap point-of-care devices," said Hughes. "We'd like to be able to use low-power handheld instruments, such as a microphone-sized ultrasound that can fit on a smartphone."

Healthcare workers and patients want fast, easy-to-use medical instruments and diagnostic tests that they can bring to a patient's bedside, home or to the field. Some treatments for disease require constant monitoring, such as blood glucose in people with diabetes or blood pressure for those with heart disease.

In DMD, muscles fail to repair themselves adequately, causing the muscles to degenerate over a few decades. Young boys and men with the disease — whom DMD hits the most — usually take steroids to prolong muscle health. Steroids have serious side effects, so patients should only take as much as they need, but it's difficult to monitor effectiveness.

Enter ultrasound. Healthy muscle contains neatly ordered cells, but DMD muscles become fibrous and plum with fat that infiltrates tissue. Because healthy and sick muscles look different in ultrasound images, researchers have been exploring how to use ultrasound to monitor progression of the disease and the muscle's response to drugs.

Previously, researchers, including Hughes, McCarthy and colleagues, have studied mice with genetic mutations that emulate muscular dystrophy. Treating mutant mice with steroids, they found they could process ultrasound information in such a way that they could measure the difference between healthy, damaged and treated muscles — a method that could put out a number on a screen.

But earlier work required more data than small, hand-held ultrasound gadgets, hooked into a smartphone with a USB cable, would be able to collect. Hughes and McCarthy wanted to know if they could also distinguish between healthy, sick and treated muscles if they collected less than 10 percent of the original data. They turned back to the ultrasound data they had collected on five healthy mice, four afflicted with mouse muscular dystrophy left untreated, and four afflicted but treated with steroids for two weeks.

To use less data, they needed to increase the relevant information in the ultrasound data and downplay the irrelevant background "noise". To do so, they used a mathematical trick called a spline, which smooths the data into average values. With a spline added to their processing program, they re-analyzed either one-eighth or one-sixteenth of the data.

The team found that even with only one-sixteenth of the data, they were able to measure the difference between the treated muscles and the untreated muscles. Of course, people have much larger muscles than mice do, so the researchers would have to adjust the amount of ultrasound data to account for that, but Hughes and McCarthy previously showed that is possible in a different study.

"If we can optimize the processing, we can increase the sensitivity and provide real-time performance," said Hughes. "People with muscular dystrophy have to take the least amount of steroid that will give them the maximum therapeutic effect. This would let them do that."

This work was supported by the National Institutes of Health and the National Science Foundation.

]]>Wed, 29 Oct 2014 21:38:00 GMT3167http://www.pnnl.gov/news/release.aspx?id=3164
Vincent A. Branton has been named General Counsel at the Department of Energy's Pacific Northwest National Laboratory. He replaces Karen Hoewing, who retired earlier this month.

Branton joined PNNL in 2003 as manager of PNNL's Intellectual Property Legal Services department, and has served as manager of PNNL's Legal department since 2008. In his new role as General Counsel, Branton will oversee both departments.

The Office of the General Counsel provides legal services including negotiations involving the PNNL operating contract, drafting and negotiating legal agreements necessary to conduct business at PNNL, employee and labor relations, environmental safety and health regulatory compliance, human subjects research, protection of intellectual property rights, litigation, client counseling, and retention and management of outside counsel. In his role as General Counsel, Branton also provides support to Battelle's Pacific Northwest Division Board of Directors.

Prior to moving to Richland, Branton worked as an engineer with Honeywell, Inc. in Clearwater, Florida, and with Lockheed Martin Energy Services, Inc. in Oak Ridge, Tennessee. After earning his juris doctorate, he served as in-house counsel for Lockheed Martin Energy Research Corporation and UT-Battelle, LLC, the operating contractor of Oak Ridge National Laboratory in Oak Ridge, Tennessee.

Branton earned a bachelor's degree in electrical engineering from the University of Tennessee-Knoxville, and a juris doctorate from Stetson University College of Law in St. Petersburg, Florida, where he was also elected to serve as editor-in-chief of the Stetson Law Review. He is a registered patent attorney and is licensed to practice law in several states.

]]>Tue, 28 Oct 2014 18:56:00 GMT3164http://www.pnnl.gov/news/release.aspx?id=3166
A new analysis of global energy use, economics and the climate shows that without new climate policies, expanding the current bounty of inexpensive natural gas alone would not slow the growth of global greenhouse gas emissions worldwide over the long term, according to a study appearing today in Nature Advanced Online Publication.

Because natural gas emits half the carbon dioxide of coal, many people hoped the recent natural gas boom could help slow climate change — and according to government analyses, natural gas did contribute partially to a decline in U.S. carbon dioxide emissions between 2007 and 2012. But, in the long run, according to this study, a global abundance of inexpensive natural gas would compete with all energy sources — not just higher-emitting coal, but also lower-emitting nuclear and renewable energy technologies such as wind and solar. Inexpensive natural gas would also accelerate economic growth and expand overall energy use.

"The effect is that abundant natural gas alone will do little to slow climate change," said lead author Haewon McJeon, an economist at the Department of Energy's Pacific Northwest National Laboratory. "Global deployment of advanced natural gas production technology could double or triple the global natural gas production by 2050, but greenhouse gas emissions will continue to grow in the absence of climate policies that promote lower carbon energy sources."

Thinking Globally

Recent advances in gas production technology based on horizontal drilling and hydraulic fracturing — also known as fracking — have led to bountiful, low-cost natural gas. Because gas emits far less carbon dioxide than coal, some researchers have linked the natural gas boom to recent reductions in greenhouse gas emissions in the United States. But could these advanced technologies also have an impact on emissions beyond North America and decades into the future?

To find out, a group of scientists, engineers and policy experts, led by PNNL's Joint Global Change Research Institute, gathered at a workshop in Cambridge, Maryland, in April 2013 to consider the long-term impact of an expansion of the current natural gas boom on the rest of the world. The researchers, hailing from the U.S., Australia, Austria, Germany and Italy, went home and projected what the world would be like in 2050 with and without a global natural gas boom. The five teams used different computer models that had been independently developed.

Their computer models included not just energy use and production, but also the broader economy and the climate system. These "integrated assessment models" accounted for energy use, the economy, and climate and the way these different systems interact with one another. The groups each computed projections halfway into the century.

Five for Five

"We didn't really know how our first experiment would turn out, but we were surprised how little difference abundant gas made to total greenhouse gas emissions even though it was dramatically changing the global energy system," said James "Jae" Edmonds, PNNL's chief scientist at JGCRI. "When we saw all five modeling teams reporting little difference in climate change, we knew we were onto something."

The key, the researchers said, is that the five different models provide an integrated, comprehensive view of the economy and the Earth system. Swapping out coal for natural gas in a simple model would cut greenhouse gas emissions, a result many people expected to see. But incorporating the behavior of the entire economy and how people create and use energy from all sources affect emissions in several ways:

Natural gas replacing coal would reduce carbon emissions. But due to its lower cost, natural gas would also replace some low-carbon energy, such as renewable or nuclear energy. Overall changes result in a smaller reduction than expected due to natural gas replacing these other, low-carbon sources. In a sense, natural gas would become a larger slice of the energy pie.

Abundant, less expensive natural gas would lower energy prices across the board, leading people to use more energy overall. In addition, inexpensive energy stimulates the economy, which also increases overall energy use. Consequently, the entire energy pie gets bigger.

The main component of natural gas, methane, is a more potent greenhouse gas than carbon dioxide. During production and distribution, some methane inevitably escapes into the atmosphere. The researchers considered both high and low estimates for this so-called fugitive methane. Even at the lower end, fugitive methane adds to climate change.

The combined effect of the three, the scientists found, is that the global energy system could experience unprecedented changes in the growth of natural gas production and significant changes to the types of energy used, but without much reduction to projected climate change if new mitigation policies are not put in place to support the deployment of renewable energy technologies.

"Abundant gas may have a lot of benefits — economic growth, local air pollution, energy security, and so on. There's been some hope that slowing climate change could also be one of its benefits, but that turns out not to be the case," said McJeon.

Scientists, engineers and economists from the following institutions contributed to the research: the JGCRI, a collaboration between PNNL and the University of Maryland, BAEconomics, the International Institute for Applied Systems Analysis, the Potsdam Institute for Climate Impact Research, the Centro Euromediterraneo sui Cambiamenti Climatici, and Resources for the Future.

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Richard Kurtz, a materials science researcher at the Department of Energy's Pacific Northwest National Laboratory has been elected to the rank of Fellow in the American Nuclear Society. ANS elects Fellows annually for contributions toward advancing the field of nuclear science and technology. The organization elects a maximum of five percent of its members to this rank each year.

Kurtz was elected for "research excellence and program leadership ... leading to significant advances in the development of damage tolerant structural materials for nuclear energy applications, including improved nondestructive inspection techniques and evaluation methods to ensure structural integrity."

Kurtz is a PNNL Laboratory Fellow in PNNL's energy and environmental research division. He is an internationally recognized expert in the field of reactor materials, particularly in the fusion reactor materials arena. Currently, he leads a program focused on developing durable, stable materials that will withstand the extremely hostile environment expected in fusion reactors of the future. These radiation-resistant materials are crucial to make fusion technically feasible, economically viable and environmentally attractive.

ANS is an international non-profit organization dedicated to promoting the awareness and understanding of the application of nuclear science and technology. The organization has more than 11,000 members representing 1,600-plus corporations, educational institutions and government agencies. Kurtz will be honored along with the rest of the 2014 Fellows at the organization's annual meeting in Anaheim, Calif., in November.